The Use of Botulinum Toxin Type A in the Healing of Thyroidectomy Wounds: A Randomized, Prospective, Placebo-Controlled Study

Abstract

Background: Recent research has indicated that botulinum toxin type A may have an inhibitory effect on the formation of fibroblasts and thus possibly decreases the severity of scar formation. Therefore, a trial was designed to assess the effects of botulinum toxin type A on scar formation after thyroid surgery. Methods: A double-blind, randomized, controlled trial was designed. All patients underwent a preoperative survey to assess scar history. All patients underwent a total thyroidectomy, hemithyroidectomy, or parathyroidectomy through a standardized incision. At the conclusion of the case, one half of the incision was injected with botulinum toxin type A, and the other half was injected with saline (placebo). The scars were then evaluated at 4 weeks, 6 months, and 1 year postoperatively using subjective scar analysis scales. Results: A total of 40 patients were enrolled. There was no significant difference in scarring at any of the time points between the botulinum toxin type A–treated and placebo sides of the incision. A subgroup analysis was performed that examined the effects of botulinum toxin type A on those with a severe scar history. This demonstrated a significant decrease in scarring at 6 months postoperatively on the botulinum toxin type A–treated side. Conclusions: This study indicates that botulinum toxin type A administration immediately after surgical closure of a thyroid incision does not demonstrate a difference in scar outcomes compared with the control side. However, there was less scarring in subjects who had a severe scar history. This study found opposite results to a similarly designed study. Further study is required to determine the optimal use of botulinum toxin type A for wound healing. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

The Safety and efficacy of botulinum toxin type A injection for postoperative scar prevention: A systematic review and meta‐analysis

“…According to the authors, this may be because this scale is applicable to the evaluation of burn scars, but not highly sensitive to nonburn scars. In the study of Phillips et al, there were no obvious difference in VSS, OSAS, and PSAS between the two groups; but the subgroup analysis found that BTXA in patients with a history of severe scars has a certain effect. The authors believe that it may be influenced by the origin of the wound and its relationship with tension lines, and speculate that the higher proportion of patients with a history of severe scars in other studies may lead to the inconsistent results .…”

“…In the study of Phillips et al, there were no obvious difference in VSS, OSAS, and PSAS between the two groups; but the subgroup analysis found that BTXA in patients with a history of severe scars has a certain effect. The authors believe that it may be influenced by the origin of the wound and its relationship with tension lines, and speculate that the higher proportion of patients with a history of severe scars in other studies may lead to the inconsistent results . However, no relevant analysis has been carried out in other included studies, and the number of cases in this study is small, with a large number of people lost to follow‐up.…”

“…Besides transient pain, pruritus, and mild headache at the injection point, there were 2 cases of ptosis, 1 case of philtrum fixation wound, 1 case of asymmetrical smile, 1 case of asymmetric oral commissure, 1 case of asymmetric eyebrow, 1 case of abscess, and 1 case of ischemia. The remaining 5 studies reported no adverse events, and 3 studies did not report …”

“…Two meta‐analysis results published by Wang and Wang before including 9 studies respectively have showed that BTXA injection is a safe and effective treatment for scar prevention, but some recent studies have reached negative conclusions . Therefore, a larger range of meta‐analysis is needed for evidence support.…”

“…Two studies calculated the dose based on body weight (1‐2 U/kg) . Others mainly determined the injection dose based on the length of the scar (1.5‐10 U/cm) or the number of injection point (0.5‐5 U/site), lacking of comparability. Considering the distribution of muscle tissue around the incision and the individual differences as well, it is difficult to determine the injection dose accurately.…”